Timing synchronization between mobile terminals and network access points are an essential aspect in many conventional radio access technologies. Accordingly, it is critical that mobile terminals obtain initial timing offset synchronization and perform Continuous timing offset tracking with one or more network access points.
Conventional mobile terminals operating on Long Term Evolution (LTE) networks obtain initial timing synchronization with a proximate cell through reception and analysis of synchronization sequences such as Primary Synchronization Signals (PSS) and Secondary Synchronization Signals (SSS). After obtaining initial timing synchronization and determining the identity of the proximate cell using PSS and SSS, a mobile terminal may perform continuous synchronization tracking using cell specific reference signals (CRS) transmitted by the proximate cell. Accordingly, timing synchronization (i.e. both initial synchronization and tracking) may be reliant on a combination of both synchronization sequences and CRS.
In conventional use cases, mobile terminals operating on LTE networks may receive both control and traffic data from a single cell, i.e. a serving cell. However, recent introductions to the 3GPP specification, such as Coordinated Multipoint (CoMP) in Release 11, may involve receiving control and traffic data from different cells, which may change over time. For example, in a Joint Transmission (JT) CoMP scheme a mobile terminal may receive control data from a serving cell and subsequently receive traffic data from a plurality of cells, i.e. to promote transmit diversity in reception of traffic data. Alternatively, in a Dynamic Point Switching (DPS) CoMP scheme a mobile terminal may receive control data from a serving cell and subsequently receive traffic data from any one of a potential set of transmitting cells, where the transmitting cell performing transmission of the traffic data may change every subframe.
Accordingly, timing synchronization in scenarios having multiple transmit locations to a single mobile terminal may require synchronization with each transmit location instead of only a single transmit location as in conventional use cases.